1. Field of the Invention
The present invention concerns very porous conductive ceramic substances and a method for the preparing thereof.
2. Description of the Prior Art
It is known that in numerous techniques, such as foundry operations, in which the flowing or treating of liquid metals is effected, the walls of the devices in contact with the liquid metal are generally made of a ceramic substance having the following characteristics:
Firstly, the ceramic substance must be passive, that is, it must not react with the liquid metal;
Moreover, that ceramic substance must be able to withstand great thermal shocks; it must therefore be porous;
Lastly, it must be dIfficult to oxidize.
The Applicant has sought to manufacture ceramic substances having the above-mentioned properties, as well as the property of transmitting easily the electric current to the molten metal, this entailing:
Fairly slight resistivity of the ceramic substance;
Good wetting of the ceramic substance by the liquid metal.